A liquid crystal display device and an organic EL (Electroluminescence) display device are represented as an example of a display device. These display devices possess a liquid crystal element or an organic light-emitting element (hereinafter, referred to as a light-emitting element) as a display element in each of a plurality of pixels formed over a substrate. A polarizing plate is disposed over the plurality of pixels to control orientation of light from the display element or suppress reflection of ambient light. A polarizing plate usually includes a poly(vinyl alcohol)-based polymer having a main chain oriented in one direction and iodine or a dichroic dye adsorbed thereto as a fundamental structure. A poly(vinyl alcohol)-based polymer readily adsorbs external water due to its high hydrophilicity. If water enters a polarizing plate, a dye or iodine is partly lost due to the water or impurities included in the water, which causes diminution of the function as a polarizing plate. Thus, Japanese Patent Application Publications No. 2010-96918, 2010-181581, and 2013-242395 disclose formation of a sealing material at an edge portion of a polarizing plate as a method for preventing entrance of water to a polarizing plate.